% refines the title, part, section and subsection commands 

\def\@maketitle{%
  \parindent 0pt \newpage \null \vskip 2em
  \begin{center}
    {\large \bf \@title} \par
    \ifx\empty\@author\else
      {\bf \@author}%
    \fi
    \ifx\empty\@date\else
      {\\\@date}%
    \fi
  \end{center}
  \par
  \vskip 1.0em
}

\def\and{\newline}
\def\section{\@startsection{section}{1}{\z@ }{-2.5ex plus -1ex minus -.2ex}
        {1.3ex plus .2ex}{\normalsize\bf}}
\def\subsection{\@startsection {subsection}{2}{\z@ }{-2.25ex plus -1ex minus -.2ex}
        {0.5ex plus .2ex}{\normalsize\bf}}
\def\subsubsection{\@startsection {subsubsection}{3}{\z@ }{-1.25ex plus -1ex minus -.2ex}
        {0.5ex plus .2ex}{\normalsize\bf}}


\def\@part[#1]#2{\ifnum \c@secnumdepth >\m@ne    % IF secnumdepth > -1
        \refstepcounter{part}                    %  THEN step part counter
        \addcontentsline{toc}{part}{\thepart     %       add toc line
        \hspace{1em}#1}\else                     %  ELSE add unnumbered line
      \addcontentsline{toc}{part}{#1}\fi         % FI
   { \parindent 0pt \raggedright 
    \ifnum \c@secnumdepth >\m@ne   % IF secnumdepth > -1 
      \Large \bf Part \thepart     %   THEN Print 'Part' and 
      \par \nobreak                %          number in \Large boldface.
    \fi                            % FI
    \Large \bf
    #2\markboth{}{}\par }          % Print title and set heading marks null.
    \nobreak                       % TeX penalty to prevent page break.
    \vskip 3ex                     % Space between title and text.
   \@afterheading                  % Routine called after part and
    }                              %     section heading.

